For detailed discussion of these quantities, one can see [1]}.
These tensors can be written in the combination of structure scalars (\(X_T\) , \(X_{TF}\) , \(Y_T\)  and \(Y_{TF}\) ).
\(X_{\alpha \beta } &=& \frac{1}{3}X_T h_{\alpha \beta }+X_{TF}\left(\chi _\alpha \chi _\beta -\frac{1}{3}h_{\alpha \beta }\right),\\Y_{\alpha \beta } &=& \frac{1}{3}Y_T h_{\alpha \beta }+Y_{TF}\left(\chi _\alpha \chi _\beta -\frac{1}{3}h_{\alpha \beta }\right).\) 
